But for civilians living in the shadow of conflict, the greatest danger is often being cut off from health services, whether due to violence or lack of development in the vast, remote areas that make up much of the country.

According to the International Committee of the Red Cross (ICRC), which supports the tiny clinic where Nyachoat is recovering in Udier village, 70 percent of all illness deaths are due to easily treatable malaria, acute watery diarrhoea and respiratory infections.

In case of more serious illness there is "no place" to go, said Nyachoat's 22-year-old mother Buk Gader.

A study by the London School of Hygiene and Tropical Medicine (LSHTM) last year showed almost 400,000 people had died as a result of South Sudan's nearly six-year war.

Half of these were due to violent deaths, and half because of the increased risk of disease and reduced access to healthcare as a result of the conflict.

"There were (aid) organisations which were supplying primary healthcare, but then during the war, most of the organisations got evacuated" and pulled out of the country, she said.

Blocked by swamps

Udier is a village with a dirt airstrip whose sun-baked sand, which when not used by twice weekly ICRC flights bringing medicine and supplies, serves as a football pitch for youths. It is also a pedestrian highway for those who come from far flung huts and cattle camps to market.

In the tiny market, there is little fresh food available. Villagers can buy red onions or sit for a strong Sudanese coffee, infused with ginger, while in the dry season nomadic Falata herdswomen in flowing dresses sell milk from their cattle.

A brick building next to the airstrip, its roof long blown off in a storm, is the village school, but for several days in a row no teacher shows up.

In the surrounding villages, women are hard at work mudding their huts and re-thatching the roof in anticipation of the rains to come within weeks.

When they do come, swelling the swampy marshlands and rivers for miles around, roads will become impassable.

It becomes "difficult for young children to swim or women or men to carry patients to reach here," said Oyenya.

Marginalised for decades prior to independence from Sudan in 2011, and engulfed in war since 2013, South Sudan has seen little development. The healthcare sector is one of many propped up by international aid organisations.

However, the country is also the most dangerous for humanitarian workers with around 100 killed over the past five years, according to United Nations figures. Dozens of organisations have been forced to pull out of areas they served due to the conflict.

The Upper Nile region, where Udier is situated near the borders of Sudan and Ethiopia, was wracked by conflict in 2017 as government forces waged a major offensive to seize the opposition-held town of Pagak.

The ICRC was forced to evacuate patients and staff from its hospital and health centre in the village of Maiwut which was looted, leaving "not even a needle on the ground", according ICRC's Oyenya.

Many relocated to Udier, which was spared from fighting.

A year later in 2018, angry protesters looted around 10 humanitarian agency compounds in the town of Maban, 72 kilometres (44 miles) north of Udier.

ICRC's head of delegation in South Sudan, James Reynolds, said a peace deal signed in September 2018 "has improved security, mobility, and access for humanitarian workers".

But fresh fighting in the southern Equatorias region "has made access to certain areas very difficult."

Women bear the burden

In opposition-held Udier, the clinic supported by the ICRC provides crucial healthcare support to the region, where like throughout South Sudan, maternal and child mortality is sky-high.

Every day a small group of patients sits outside under a fragrant Neem tree, waiting to be helped, some from nearby while others have walked for a day or two.

Oyenya says a major challenge is that women, who do all the heavy work and take care of up to 10 children, may delay bringing them to the centre in time. That can be deadly.

Sometimes the children come alone: a nine-year-old girl in a purple polka dot dress confidently tells Oyenya she is suffering from bloody diarrhoea and, she thinks, malaria. Her parents are nowhere in sight.

For anything more serious, such as pregnancy complications, blood transfusions and operations, the nearest hospital is in government-held Maban, a five-hour drive away or a three-day walk.

The other option is a three-day walk to Gambella in Ethiopia.

"They may reach there alive, or they may not reach there alive," said Oyenya.